As old and highly intelligent citizen of Montreal, and formerly a member of the City Council, calls our attention to this subject. It is one that he has specially studied, and his views are entitled to particular respect. He notices the fact that the City Fathers, despite the recommendation of the Road Committee, think it cheaper and therefore better to use broken lime-stone instead of whin-stone or banc-rouge, for macadamizing the streets of the city. This our correspondent assures us, and we also believe is a serious error on many grounds. The cost of the two kinds of stone, before breaking, we understand, is about the same; but the whin-stone, being much harder, costs more in breaking, and therefore costs more to put down. It is better to pay the extra cost? We believe it is sufficiently proved that the greater durability of the harder stone, makes it cheaper in the long run. We are informed that the Montreal Turnpike Trust have sufficiently demonstrated this fact by their experience. They, therefore, use the hard stone altogether on roads, which although travelled over a good deal, are scarcely required to stand the wear and tear of the streets of Montreal. And those of our readers who indulge in drives in the vicinity of the city know well, the luxury of the smooth turnpike roads was compared with the rough streets in Montreal. We should think that these considerations on the question of cost should be decisive if they are well founded, and the City Fathers can easily satisfy themselves with the necessary proof. Streets are not made to last for a year, but for many years. There are yet other considerations of the health of the citizens, which, in the opinion of the majority, will be held to be paramount. It is known that limestone grinds or pulverizes into an almost impalpable powder, by the constant passing of wheels and iron-clad hoofs upon it. This does not, in the [illegible] of summer, required a very strong breeze to blow into great clouds of suffocating dust—dust that permeates everywhere, into one’s eyes, nostrils, lungs; into one’s clothes, offices, sitting rooms, sleeping rooms; it is subtle and pervading and [illegible] to be kept out; it is in fact reminds one of the sand storms of which one reads in the desert, and it injurious influence must be great—greater than is commonly supposed. The whin-stone, covered with [illegible] grinds comparatively little, add on this account is greatly to be preferred. In the old country good macadamized roads are as hard and smooth as many of the railroads on this continent. Some of the most thronged and fashionable streets of London are macadamized, and worn as levels as [illegible]. Every consideration calls for doing well—for doing is the best manner, whatever is done in macadamizing the streets of Montreal. The best is, in the long run, the cheapest for the pockets, and the health of the citizens.